﻿/*字母转换 
Time Limit:1000MS  Memory Limit:32768K

  
	Description:
	将字母的大小写转换一下，非字母字符原样输出。 
	
	  Sample Input:
	  I like ACM/ICPC.
	  Hello World!

Sample Output:
i LIKE acm/icpc.
hELLO wORLD!

*/

#include <stdio.h>
#include <ctype.h>
#define MAX_CHARS 128

int main(int argc, char* argv[])
{
	char line[MAX_CHARS]={0};
	while(gets(line))
	{
		char *p;
		for (p=line; *p; ++p)
			if(islower(*p))*p=toupper(*p);
			else if(isupper(*p))*p=tolower(*p);
		puts(line);
	}

	return 0;
}
